From patent specification U.S. Pat. No. 2,373,764 an escalator has become known in which the handrail is guided over an upper reversing-wheel which drives the handrail and over a lower, free-running reversing-wheel. The upper reversing-wheel has a pulley which is coaxial with the reversing-wheel and drivable by means of a chain, the chain being drivable by means of a pulley of the step-chain reversing-wheel. The driving energy for the step-chain is provided by an electric motor and gearbox.
A disadvantage of such a device is that the handrail-drive can only be used with encapsulated or enclosed reversing-wheels. The centrally arranged pulley with the driving chain must be covered in all situations for reasons of safety.